It is well known to use anchoring devices comprising a barrel and a wedge as an anchoring device for tendons, such as steel tendons or fiber reinforced polymer (FRP) tendons. The wedge clamps the steel or FRP tendons mechanically using pressure and friction.
WO 2010/047634 A1 discloses an anchoring device comprising a sleeve (1) with an internal conical space and a wedge element (7). The wedge element is provided with grooves (11,12) which has an extent in both axial and radial directions relative to the central axis of the anchoring device.
However, when anchoring FRP tendons due to the strength properties of the FRP tendons fibers in the transverse direction are poor and the mechanical anchorage have to rely on friction using large compressive stresses from the clamping device known anchoring devices may cause problems as high principal stresses acting on the tendons in the loaded end (proximal end) of the anchorage device, where both tensile and compressive forces are represented, often resulting in premature failure.
As the tension stresses on the tendons are high at the proximal end of the anchoring device, it is advantageous to decrease the radial stresses to decrease the principal stresses at the proximal end of the anchoring device.
Furthermore, to increase the capacity of an anchoring system comprising a barrel and a wedge, it is desirable to provide an anchorage device which increases the grip of the tendons without premature failure.